12,307 research outputs found
Inventory and Assessment of Cultural Resources Above the 1,551.5-Foot Contour Line, Stacy Reservoir Recreation Areas, Concho, Coleman, and Runnels Counties, Texas
In August and September 1986, personnel from Prewitt and Associates, Inc. conducted an inventory and assessment of cultural resources in five recreational area tracts above the conservation pool elevation of the proposed Stacy Reservoir in Concho, Coleman. and Runnels counties, Texas. These investigations were sponsored by the Colorado River Municipal Water District in compliance with federal requirements for a construction permit from the Corps of Engineers. Approximately 1,690 acres were surveyed. and five previously unrecorded sites were discovered and documented. Cairn feature sites 41CC213 and 41CC237 are deemed potentially significant and should be preserved or investigated to determine their significance if preservation cannot be assured. In the course of the survey. 16 previously recorded sites were encountered and. in the case of 5 of these sites. adjustments were made in their boundaries. Concurrent with the survey. 11 localities and 34 sites within the previously surveyed conservation pool area were revisited. A preliminary examination of the geologic context of these sites was conducted which resulted in recognition of important geoarcheological data potential for sites in the alluviated valleys of the project area
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Texas Business Review, March 1975
The Business Situation in Texas; Growth of the Texas Economy, 1959-1974; Texas Construction; The Energy Economy: U.S. Oil Imports and Exports, 1860-1974Bureau of Business Researc
Supermassive black holes as the regulators of star formation in central galaxies
We present a relationship between the black hole mass, stellar mass, and star
formation rate of a diverse group of 91 galaxies with dynamically-measured
black hole masses. For our sample of galaxies with a variety of morphologies
and other galactic properties, we find that the specific star formation rate is
a smoothly decreasing function of the ratio between black hole mass and stellar
mass, or what we call the specific black hole mass. In order to explain this
relation, we propose a physical framework where the gradual suppression of a
galaxy's star formation activity results from the adjustment to an increase in
specific black hole mass and, accordingly, an increase in the amount of
heating. From this framework, it follows that at least some galaxies with
intermediate specific black hole masses are in a steady state of partial
quiescence with intermediate specific star formation rates, implying that both
transitioning and steady-state galaxies live within this region known as the
"green valley." With respect to galaxy formation models, our results present an
important diagnostic with which to test various prescriptions of black hole
feedback and its effects on star formation activity.Comment: 15 pages, 4 figures, 2 tables. Accepted for publication in The
Astrophysical Journa
NASA MSFC hardware in the loop simulations of automatic rendezvous and capture systems
Two complementary hardware-in-the-loop simulation facilities for automatic rendezvous and capture systems at MSFC are described. One, the Flight Robotics Laboratory, uses an 8 DOF overhead manipulator with a work volume of 160 by 40 by 23 feet to evaluate automatic rendezvous algorithms and range/rate sensing systems. The other, the Space Station/Station Operations Mechanism Test Bed, uses a 6 DOF hydraulic table to perform docking and berthing dynamics simulations
Hope and glory: an expanded social strategy diagnosis model to incorporate corporate social responsibility within business strategy
YesCorporate social responsibility has been seen by corporations as a
practice to adopt as an act of philanthropy. There have been attempts to expand
the role of social responsibility to business problems however there has never
been an attempt to consider the strategic alignment of social outcomes to
strategy. This article analyses the role of strategy by providing a review of
strategy using Whittington’s generic strategies model and expanding the same
model to incorporate a social strategy model that supports the anecdotal idea
that social responsibility can be potentially strategic. The paper centres its
argument within the Indian context
Simulating Star Formation and Feedback in Galactic Disk Models
We use a high-resolution grid-based hydrodynamics method to simulate the
multi-phase interstellar medium in a Milky Way-size quiescent disk galaxy. The
models are global and three-dimensional, and include a treatment of star
formation and feedback. We examine the formation of gravitational instabilities
and show that a form of the Toomre instability criterion can successfully
predict where star formation will occur. Two common prescriptions for star
formation are investigated. The first is based on cosmological simulations and
has a relatively low threshold for star formation, but also enforces a
comparatively low efficiency. The second only permits star formation above a
number density of 1000 cm^-3 but adopts a high efficiency. We show that both
methods can reproduce the observed slope of the relationship between star
formation and gas surface density (although at too high a rate for our adopted
parameters). A run which includes feedback from type II supernovae is
successful at driving gas out of the plane, most of which falls back onto the
disk. This feedback also substantially reduces the star formation rate.
Finally, we examine the density and pressure distribution of the ISM, and show
that there is a rough pressure equilibrium in the disk, but with a wide range
of pressures at a given location (and even wider for the case including
feedbackComment: 14 pages, 12 figures, accepted to Astrophysical Journa
Fault-Tolerant Thresholds for Encoded Ancillae with Homogeneous Errors
I describe a procedure for calculating thresholds for quantum computation as
a function of error model given the availability of ancillae prepared in
logical states with independent, identically distributed errors. The thresholds
are determined via a simple counting argument performed on a single qubit of an
infinitely large CSS code. I give concrete examples of thresholds thus
achievable for both Steane and Knill style fault-tolerant implementations and
investigate their relation to threshold estimates in the literature.Comment: 14 pages, 5 figures, 3 tables; v2 minor edits, v3 completely revised,
submitted to PR
Modeling Pauli measurements on graph states with nearest-neighbor classical communication
We propose a communication-assisted local-hidden-variable model that yields
the correct outcome for the measurement of any product of Pauli operators on an
arbitrary graph state, i.e., that yields the correct global correlation among
the individual measurements in the Pauli product. Within this model,
communication is restricted to a single round of message passing between
adjacent nodes of the graph. We show that any model sharing some general
properties with our own is incapable, for at least some graph states, of
reproducing the expected correlations among all subsets of the individual
measurements. The ability to reproduce all such correlations is found to depend
on both the communication distance and the symmetries of the communication
protocol.Comment: 9 pages, 2 figures. Version 2 significantly revised. Now includes a
site-invariant protocol for linear chains and a proof that no limited
communication protocol can correctly predict all quantum correlations for
ring
The application of airborne imaging radars (L and X-band) to earth resources problems
For abstract, see N75-24064
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